In general, leadership seems to be about influencing others to do something. Inspiration or motivation may be the tools of leadership influence, and there are certainly others that can be used (such as coercion or power). Leadership is an interpersonal action that has mostly been understood as one person leading several others and that the leader has an involvement in the results of the action. I think this last part is useful to consider because if leadership is solely about influence then it could be anything from sales to bribery (perhaps it is).